Department of Physics and Optical Science, University of North Carolina at Charlotte, Charlotte, NC 28223, USA.

Abstract

BACKGROUND AND OBJECTIVES:

A noninvasive approach to vasectomy may eliminate male fear of complications related to surgery (e.g., hematoma, infection, acute and chronic pain, sterilization failure) and increase its acceptance. Noninvasive laser thermal occlusion of the canine vas deferens has recently been reported. In this study, high-frequency ultrasound is used to confirm successful laser thermal coagulation and scarring of the vas in a short-term canine model.

MATERIALS AND METHODS:

Bilateral noninvasive laser coagulation of the vas was performed in a total of nine dogs using a laser wavelength of 1,075 nm, incident power of 9.0 W, pulse duration of 500 milliseconds, pulse rate of 0.5 Hz, and 3-mm-diameter spot. Cryogen spray was used to cool the scrotal skin surface and prevent burns during the procedure. A clinical ultrasound system with a 13.2-MHz high-frequency transducer was used to image the vas before and after the procedure. Burst pressure measurements were performed on excised vas to confirm thermal occlusion.

Representative high-frequency ultrasound images of the canine vas deferens: (a) At Day 0 before the procedure; (b) At Day 0 immediately after the procedure; and (c) At Day 28 at the completion of the study. Note the disruption of the vas deferens structure in the region that was targeted by the laser. The blue and red colors represent Doppler imaging of blood flow through the testicular artery in the spermatic cord.

Representative images of the canine scrotal skin surface: (a) At Day 0 before the procedure; (b) At Day 0 immediately after the procedure; and (c) At Day 28 at the completion of the study. Note that much of the skin irritation observed immediately after the procedure is due to the vasectomy ring clamp used to isolate the vas underneath the skin. This irritation is temporary and disappears soon after the procedure.